Process of coking pitch



Patented June 2, 1936 l l UNITED STATES PATENTVOFFICE V I t PRUCESS v l Daniel Tollie Smith, Wylam, Ala., assignor ,to The Barrett Company, New York, N. Y., a corporation of New Jersey Application February 28; 1933, Serial No. 658,912 3 Claims. (01.202-6) This invention relates to the coking of hydro- '2000" F.', determined by means of an electrical carbon material, and more particularly, to the p yrometer, the thermo-couple of which is placed in a beehive i te ivfiifi tii tintlifitfifi afiiitofii duce har fir r o e oor.

In the Hali g)a efi t l l o. of November of the beehive oven reaches the point hereinabove 5 22, 1927, there is disclosed 511121 l i d pro.v indicated, the coke is quenched with an amount 1 cedure of coking coal tar pitch in a beehive. oven' of wat r ju t sufli to quench th coke, r s whic results in the production of a hard, fi m, mg m alowerlng of the temperature at the Filogr metallurgical coke. The process of this patent o th v n t a t m a e e z g g yieldsanimpmved *xtremdyhigMWn $2 51; ititi iff eiti ii inioitad i352, tie

l a e v ZZEI fc atZfr i 'iS even, vthe h mp a ur s pr vailin t e n the nature of a, specific improvement on t proinitiating combustion of'the volatiles in the pitch. cedure of the Hall patent, The introduction of the pitch results in a further A5 a s t of extensive development work, I lowering of the temperature in a beehive oven. 15 h fdund t t the quality of coke produced b During the introduction of the pitch and for some 1 time thereafter the temperature may drop about coking coal tarv pitch or other hydrocarbons is ft h th I bustion within materially afiected by the temperature of the ofl'n' gggig fixe g ng fig d t t pe oven bemg 1 1 is to fi g fi i ature rises graduallyso that at the end of about 20 grads (Rf -meta urglca 1 3 2 befgre forty (40) hours, the temperature reaches from fi lt g 3 3 3: g ggi m 3f 3 Oven about 1500 F. to about 2000 F. and the cokingis e r e d l l ed mot: than is necessary in cooling the completed- At this point, the coking is n' oven after the completion of the coking of one tmued the coke Q i gndgvltadmwni and a 5 charge, it will frequently be found that the coke Trish charge g f 3 h-owever that obtained from the next charge of coke vwill have t n e fgg (mime floor hr the green ends and an excessively high volatile con-- o v n iil d ife t cont l afz t with the coke will not ortent on the other If the oven 15 not coined dinarily give a reliable record of the temperature sufliciently, the coking of the next charge of pitch t th no f the oven during the coking of suc 90 will result in semi-foamy or foamy coke and not g 0 8 since the tem erature in proxv hardtfirm dense coke one possible fi i l i ity ti thg ig'ie rmo-couple witlfin the oven is at. for the latter phenomenon is that if t e floor o v 3:: it; t t amounts of t, and upcnm q e cks. In order to obtain a reliable indication of a fresh charge of pitch the ovfm thls of the temperature within the oven and at the rushes Into the coal tar mtch causmg foammg floor thereof, it is preferred to place the thermothereof and prematurecokmg of portions of the couple beneath the floor out of contact with the charge 37nd the formation of it? foamy coke. In the case of a circular beehive oven hav- I have found that the queue a 2 remgva ing a floor layer of refractory material, e. g., gan- 40 cPke from the Oven whene empera-ure ister four inches thick, a clay layer five inches within the oven reaches a definite predetermined thick beneath the refractory layer an asbestos range resultsvm the Own having a suitabletem' layer four inches thick beneath the clay layer perature: for the reception and coking of a subseand a concrete foundation twenty-four inches quent pltch char-g8 and that by queue-hing apd thick I placed the thermo-couple of the pyrome- 5 removing successive charges within this definite ter the top of the asbestos layer, nine inchsl temperature hard densecoke of beneath the floor, with the end of the thermogood quality 15 umfprmly m f couple disposed near the center of the oven floor.

In accordance. with my Invention the 00km? At this point, the temperature effect on the therof a charge of six tons of P tar pitch of 400 mo-couple provided an accurate indication of the melting point in beehwe oven or the type temperature conditions within the oven. With shown on the drawing having floor diameter of the thermo-couple positioned as hereinabove de-- and an altitude of 0 /2", is di c nscribed and coking coal tar pitch of 400 F. melttinued when the temperature at the floor of the ing point, I found that the pulling of the oven,

oven reaches a temperature of from 1500" F. to l. e., the quenching of the coke in the oven 101- was completely cokcd lowed by the removal of the coke, when the pyrometer showed a temperature within the range of from 900 F. to 1100 F., and preferably within the range of from 900 F. to 1000 F., the charge and firm, dense coke resulted. Water was introduced into the oven in amount sufllcient to quench the coke, e. g., 85 gallons of water per ton'of coke produced, and the oven thus cooled to a temperature of 800 F. for the reception of the next charge.

In the drawing- Fig. 1 is a vertical section through a beehive oven for coking coal tar pitch, equipped with a thermo-couple beneath the floor of the oven, and

Fig. 2 is a plan section of the oven of Fig. 1

taken in a. horizontal plane passing through line 2-2 of Fig. 1.

In the drawing, reference numeral l indicates a concrete foundation which may be approximately twenty-four inches thick for a beehive oven 2. Disposed on the foundation I is a layer,

approximately-four inches thick, of loose asbestos 3 tamped into place on top of the concrete foundation I. On top of the asbestos layer 3 is a clay layer 4, approximately five inches thick. The floor proper 5 of the oven 2 is constituted of a refractory layer, e. g., ganister, approximately four inches thick. As customary, the beehive oven 2 is provided with a charging hole 6 which may be closed by means of a suitable closure (not shown), a flue I through which products of combustion may escape from the oven, and an opening or port 8 through which air or other oxygen-containing gas may be admitted to support combustion of the volatile matter during the beehive coking of the pitch, and after quenching of the coke in the oven, the coke may be withdrawn. The quenching water may be introduced through charging hole 6.

A thermo-couple well 9 is disposed on top of the asbestos layer 3. This well may be formed by placing a suitable pipe, as shown in Fig. 2, with the end ll of the pipe disposed near the center of the floor of the 'oven. A thermo-coupie is disposed in thewell 9. With the thermocouple positioned as hereinabove described, an accurate representation of the temperature conditions within the oven,particularly in the floor thereof, is given by the pyrometer with which the thermo-couple communicates.

In coking hydrocarbon material in an oven, as shown in the drawing, the charge is withdrawn from the hot oven when the pyrometer chart, on which the temperatures to which the thermo-couple is subjected are recorded, shows a temperature within the range of from 900 to 1100 F., preferably within the range of from 900 to 1000 F. With 400 F. melting point coal tar pitch and a charge of six tons of pitch in an oven of the type shown on the drawing, the coking time required will be approximately 52 hours. This represents a reduction of the order of 8 hours in coking timev as compared with the coking time heretofore customarily employed in coking coal tar pitch of like melting point. Furthermore, an increase in the amount of high quality coke produced results from the practice of my invention and the coke formed .is of uniformly good quality, the production of spongy, foamy coke being eliminated.

Since certain changes may be made in carrying out the above process without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

i. The process of coking successive charges oi 10 pitch in a beehive oven heated to a temperature such that the floor of the oven is at a temperature of from about 600 F. to about 800 F. which comprises introducing a charge of coal tar pitch into said heated oven, introducing a combustionsupporting gas into said oven to burn volatile matter in said coal tar pitch and to heat the latter to form coke, quenching the coke when the floor of said oven reaches. a temperature of from about 1500 F. to about 2000" F. thereby resulting in a lowering of the temperature of the oven,

removing the coke when the temperature at the floor of the oven reaches a temperature of from about 600 F. to about 800 F. and then introducing the next charge of coal tar pitch into the oven, the introduction of the said charge of coal tar pitch resulting in a iurther lowering of the temperature at the floor of the oven to a temperature of from about 400 F. to about 600 F.

2. The process of coking successive charges oi pitch in a beehive oven heated to a temperature such that the floor of the oven is at a temperature of from about 600 F. to about 800 F. which comprises charging coal tar pitch into said heated oven, admitting air into said oven to burn a portion of said coal tar pitch, until said oven floor reaches a temperature falling within a predetermined range 0! from about 1500 F. to about 2000 F., and the pitch is coked, quenching the resultantcoke'until the floor of the oven reaches 40 a predetermined temperature within the range of from about 600 F. to about 800 F., removing the coke from said oven and introducing the next charge of coal tar pitch into said oven.

3.'The process of coking coal tar pitch in a beehive oven having a refractory floor approximately four inches thick, a layer of clay approximately five inches thick beneath the floor, a layer of asbestos approximately four inches thick beneath the layer of clay, and a concrete ioundation approximately twenty-four inches thick beneath the layer of asbestos, the steps which comprise introducing coal tar pitch into said beehive oven which has been heated bya previous coking operation, the temperature of said oven at the beginning of the introduction of said coal tar pitch indicated on a thermo-couple pfaced on top of the layer of asbestos and positioned approximately in the center of the floor of the oven being about 800 F., cokingthe coal tar pitch in the oven by burning a portion thereof by means of air admitted thereto until the said thermo-couple indicates a temperature within the range of from about 900 F. to about 1000 F. .and the pitch is (coked, immediately thereaft- 5 er introducing water into the oven in an amount sufficient only to quench the coke and to. reduce the temperature indicated on said thermo-couple to about 800 F., and then removing the coke.

DANIEL TOLLIE SMITH. 

